Powered Combat Vest (PCV)
The Powered Combat Vest, commonly abbreviated as P.C.V. is a protective vest worn by the Marines of the Hazardous Environment Combat Unit and Military Police, over which the LC-2 Harness is worn. Upon military approval, it entered use by the Hazardous Environment Combat Unit and certain elements of the Military Police. Part of the combat equipment used by the HECU in their initial incursion into Black Mesa and during the events that occur throughout Half-Life ''storyline, the PCV is designed to protect the user from chemical, biological, radiological and physical threats during operations in the unit's defined battle space. The vest increases the effectiveness and versatility of the user, allowing them to operate in environments which are outside the normal bounds of the regular infantry. The PCV is compatible with a gas mask resembling the M40 Field Protective Mask with built-in Night-Vision Goggles. In addition, the PCV includes a Geiger counter, morphine administrator (which allows the soldier to function normally even after serious injury), a Tactical Radio and a Head-Up Display (HUD) in the protective mask lens which tracks the user's medical condition and weapon ammunition. The vest contains an on-board computer system that constantly monitors the user's health and vital signs and reacts to any changes in the user's condition, although, unlike the HEV, there's no audible computer that alerts the user and is instead used a HUD in the helmet. Like the HEV, it absorbs 66 percent of the damage the player takes. Additionally, during the events seen in gameplay, the PCV provides complete protection to the center mass of the user, protecting the torso, abdomen, shoulders, and back. This is provided by the electrically powered shield which stiffens the fibers of the suit to provide a hard, resilient layer of armor to absorb the kinetic energy. With a fully charged vest, the user can survive several dozen rounds of small arms fire or even a direct hit from a rocket propelled grenade. The PCV also provides protection from high level electrical and thermal energy, biological and chemical threats when sufficiently charged. The PCV can be charged by power modules either from the operational area or specially designed models which form part of the unit's arsenal. It may be noted that the PCV is comparable to the HEV Suit, which is worn by several Black Mesa personnel, including Gordon Freeman. This similarity is mostly attributed to the types of equipment included in both. In addition, the Powered Combat Vest's armor charge is also rechargeable at civilian, military or government electrical chargers, including those that are designed specifically for HEV Suits. This has led to fans speculating that the PCV is either a precursor, or a derivative of the HEV. However, the PCV includes night vision goggles as opposed to the HEV Suit's flashlight. This suggests that the PCV is simply a military adaptation of HEV technology, combining the level of protection of an HEV Suit (which exceeds that of current ballistic vest technology) with night-vision technology that gives soldiers the considerable advantage of being able to operate at night. Another speculation is that since the PCV is military hardware designed for the battlefield where chargers are limited while the HEV is for research, the Powered Combat Vest's batteries may be designed to take in energy from whatever source available. While the ''Half-Life storyline suggests that both the PCV and HEV Suit are separate pieces of equipment, the similarities between both may simply be the result of Opposing Force's programmers modifying the HEV Suit's interface from Half-Life to that of a PCV for Opposing Force.